This study of commercial truck drivers will address the prevention of poor health status, injuries, chronic illnesses and diseases by: Aim (1) identifying risk factors and prevalence of these problems among 1,000 commercial truck drivers from a cross sectional study drawn from many companies in 2 diverse states, Aim (2) comparing the most recent Commercial Driver Medical Examination (CDME) results with additional questions, blood tests and urinalyses for potential improvements in the CDME, and Aim (3) developing and pilot-testing a truck driver health promotion program (Worksite Health, Eating and Exercising for the Long Haul, WHEEL). This study is designed to emphasize the factors that shorten truck driver's careers, result in shortened CDL certifications (<2-year max.), and provide risks for motor vehicle crashes and other injuries. Aim 1. The spectrum of problems we are investigating includes the most common reasons for driver restrictions: diabetes mellitus, obesity, physical inactivity, hypertension, dyslipidemia, cardiovascular disease, tobacco use, sleep disorders, low back pain and over the counter and prescription medication use. Methods will include electronically administered questionnaires in small groups;measured height, weight, blood pressure, heart rate, neck/chest/waist/hip circumferences, urinalyses, and blood testing for fasting glucose, hemoglobin A1c, lipid profile, and highly sensitive C-reactive protein. Questions include self reported motor vehicle crashes, near-miss crashes, and records of crashes. A nested case-control study will assess vibration exposures (random selection of 50 cases with and 100 controls without low back pain). Aim 2. Each subject's most recent CDME information will be evaluated by a blinded panel of physicians to categorize certification status. They will also separately categorize the CDME status based upon all measures from the entire battery of results from this study. Those factors found to be most important in changing certification status will be the highest candidates for recommendations to improve the CDME. Aim 3. Focus groups, questionnaires and truck stop visits will be used to develop the WHEEL program aimed at weight reduction considering the unique needs of these workers, including those risk factors and illnesses that preclude or shorten certifications. WHEEL will be pilot-tested on 35 truck drivers for acceptance and to determine effect size for design of a full intervention.